scholarly journals Soluble Polysaccharide Derived from Laminaria japonica Attenuates Obesity-Related Nonalcoholic Fatty Liver Disease Associated with Gut Microbiota Regulation

Marine Drugs ◽  
2021 ◽  
Vol 19 (12) ◽  
pp. 699
Author(s):  
Yiping Zhang ◽  
Longhe Yang ◽  
Nannan Zhao ◽  
Zhuan Hong ◽  
Bing Cai ◽  
...  

In this study, the effects of a polysaccharide derived from Laminaria japonica (LJP) on obesity were investigated in mice fed a high-fat diet (HFD). LJP significantly attenuated obesity-related features, lowering serum triglycerides, glucose, total cholesterol and low-density lipoprotein cholesterol levels. HFD-induced liver steatosis and hepatocellular ballooning were significantly attenuated by LJP. Additionally, LJP was found to significantly modulate hepatic gene expressions of AMPK and HMGCR, which are key regulators of lipid and cholesterol metabolism. We further found that LJP ameliorated HFD-induced gut microbiota (GM) dysbiosis by significantly reducing the obesity-related Firmicutes to Bacteroidetes ratio, meanwhile promoting the growth of Verrucomicrobia at the phylum level. At the genus level, propionate-producing bacteria Bacteroides and Akkermansia were elevated by LJP, which might explain the result that LJP elevated fecal propionate concentration. Taken together, these findings suggest that dietary intake of LJP modulates hepatic energy homeostasis to alleviate obesity-related nonalcoholic fatty liver disease associated with GM regulation.

2021 ◽  
Vol 22 (12) ◽  
pp. 6485
Author(s):  
Francesca Fianchi ◽  
Antonio Liguori ◽  
Antonio Gasbarrini ◽  
Antonio Grieco ◽  
Luca Miele

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of liver disease worldwide, affecting both adults and children and will result, in the near future, as the leading cause of end-stage liver disease. Indeed, its prevalence is rapidly increasing, and NAFLD is becoming a major public health concern. For this reason, great efforts are needed to identify its pathogenetic factors and new therapeutic approaches. In the past decade, enormous advances understanding the gut–liver axis―the complex network of cross-talking between the gut, microbiome and liver through the portal circulation―have elucidated its role as one of the main actors in the pathogenesis of NAFLD. Indeed, evidence shows that gut microbiota is involved in the development and progression of liver steatosis, inflammation and fibrosis seen in the context of NAFLD, as well as in the process of hepatocarcinogenesis. As a result, gut microbiota is currently emerging as a non-invasive biomarker for the diagnosis of disease and for the assessment of its severity. Additionally, to its enormous diagnostic potential, gut microbiota is currently studied as a therapeutic target in NAFLD: several different approaches targeting the gut homeostasis such as antibiotics, prebiotics, probiotics, symbiotics, adsorbents, bariatric surgery and fecal microbiota transplantation are emerging as promising therapeutic options.


2020 ◽  
Author(s):  
Olena H. Kurinna

AbstractNonalcoholic fatty liver disease (NAFLD) bears serious economic consequences for the health care system worldwide and Ukraine, in particular. Cardiovascular diseases (CVD) are the main cause of mortality in NAFLD patients. Changes in the gut microbiota composition can be regarded as a potential mechanism of CVD in NAFLD patients.The purpose of this work was to investigate changes in major gut microbiota phylotypes, Bacteroidetes, Firmicutes and Actinobacteria with quantification of Firmicutes/Bacteroidetes in NAFLD patients with concomitant CVD.The author enrolled 120 NAFLD subjects (25 with concomitant arterial hypertension (AH) and 24 with coronary artery disease (CAD)). The gut microbiota composition was assessed by qPCR.Resultsthe author found a marked tendency towards an increase in the concentration of Bacteroidetes (by 37.11% and 21.30%, respectively) with a decrease in Firmicutes (by 7.38% and 7.77%, respectively) in both groups with comorbid CAD and AH with the identified changes not reaching a statistical significance. The author quantified a statistically significant decrease in the concentration of Actinobacteria in patients with NAFLD with concomitant CAD at 41.37% (p<0.05) as compared with those with an isolated NAFLD. In patients with concomitant AH, the content of Actinobacteria dropped by 12.35%, which was statistically insignificant.Conclusionsthe author established changes in the intestinal microbiota, namely decrease in Actinobacteria in patients with CAD, which requires further research.


Author(s):  
Jiake Yu ◽  
Hu Zhang ◽  
Liya Chen ◽  
Yufei Ruan ◽  
Yiping Chen ◽  
...  

Children with nonalcoholic fatty liver disease (NAFLD) display an altered gut microbiota compared with healthy children. However, little is known about the fecal bile acid profiles and their association with gut microbiota dysbiosis in pediatric NAFLD. A total of 68 children were enrolled in this study, including 32 NAFLD patients and 36 healthy children. Fecal samples were collected and analyzed by metagenomic sequencing to determine the changes in the gut microbiota of children with NAFLD, and an ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) system was used to quantify the concentrations of primary and secondary bile acids. The associations between the gut microbiota and concentrations of primary and secondary bile acids in the fecal samples were then analyzed. We found that children with NAFLD exhibited reduced levels of secondary bile acids and alterations in bile acid biotransforming-related bacteria in the feces. Notably, the decrease in Eubacterium and Ruminococcaceae bacteria, which express bile salt hydrolase and 7α-dehydroxylase, was significantly positively correlated with the level of fecal lithocholic acid (LCA). However, the level of fecal LCA was negatively associated with the abundance of the potential pathogen Escherichia coli that was enriched in children with NAFLD. Pediatric NAFLD is characterized by an altered profile of gut microbiota and fecal bile acids. This study demonstrates that the disease-associated gut microbiota is linked with decreased concentrations of secondary bile acids in the feces. The disease-associated gut microbiota likely inhibits the conversion of primary to secondary bile acids.


2021 ◽  
Vol 22 (18) ◽  
pp. 9969
Author(s):  
Mariano Schiffrin ◽  
Carine Winkler ◽  
Laure Quignodon ◽  
Aurélien Naldi ◽  
Martin Trötzmüller ◽  
...  

Men with nonalcoholic fatty liver disease (NAFLD) are more exposed to nonalcoholic steatohepatitis (NASH) and liver fibrosis than women. However, the underlying molecular mechanisms of NALFD sex dimorphism are unclear. We combined gene expression, histological and lipidomic analyses to systematically compare male and female liver steatosis. We characterized hepatosteatosis in three independent mouse models of NAFLD, ob/ob and lipodystrophic fat-specific (PpargFΔ/Δ) and whole-body PPARγ-null (PpargΔ/Δ) mice. We identified a clear sex dimorphism occurring only in PpargΔ/Δ mice, with females showing macro- and microvesicular hepatosteatosis throughout their entire life, while males had fewer lipid droplets starting from 20 weeks. This sex dimorphism in hepatosteatosis was lost in gonadectomized PpargΔ/Δ mice. Lipidomics revealed hepatic accumulation of short and highly saturated TGs in females, while TGs were enriched in long and unsaturated hydrocarbon chains in males. Strikingly, sex-biased genes were particularly perturbed in both sexes, affecting lipid metabolism, drug metabolism, inflammatory and cellular stress response pathways. Most importantly, we found that the expression of key sex-biased genes was severely affected in all the NAFLD models we tested. Thus, hepatosteatosis strongly affects hepatic sex-biased gene expression. With NAFLD increasing in prevalence, this emphasizes the urgent need to specifically address the consequences of this deregulation in humans.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Jinsheng Yu ◽  
Sharon Marsh ◽  
Junbo Hu ◽  
Wenke Feng ◽  
Chaodong Wu

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world, and it comprises a spectrum of hepatic abnormalities from simple hepatic steatosis to steatohepatitis, fibrosis, cirrhosis, and liver cancer. While the pathogenesis of NAFLD remains incompletely understood, a multihit model has been proposed that accommodates causal factors from a variety of sources, including intestinal and adipose proinflammatory stimuli acting on the liver simultaneously. Prior cellular and molecular studies of patient and animal models have characterized several common pathogenic mechanisms of NAFLD, including proinflammation cytokines, lipotoxicity, oxidative stress, and endoplasmic reticulum stress. In recent years, gut microbiota has gained much attention, and dysbiosis is recognized as a crucial factor in NAFLD. Moreover, several genetic variants have been identified through genome-wide association studies, particularly rs738409 (Ile748Met) inPNPLA3and rs58542926 (Glu167Lys) inTM6SF2, which are critical risk alleles of the disease. Although a high-fat diet and inactive lifestyles are typical risk factors for NAFLD, the interplay between diet, gut microbiota, and genetic background is believed to be more important in the development and progression of NAFLD. This review summarizes the common pathogenic mechanisms, the gut microbiota relevant mechanisms, and the major genetic variants leading to NAFLD and its progression.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Caihua Wang ◽  
Chunpeng Zhu ◽  
Liming Shao ◽  
Jun Ye ◽  
Yimin Shen ◽  
...  

Nonalcoholic fatty liver disease (NAFLD) is a major health threat around the world and is characterized by dysbiosis. Primary bile acids are synthesized in the liver and converted into secondary bile acids by gut microbiota. Recent studies support the role of bile acids in modulating dysbiosis and NAFLD, while the mechanisms are not well elucidated. Dysbiosis may alter the size and the composition of the bile acid pool, resulting in reduced signaling of bile acid receptors such as farnesoid X receptor (FXR) and Takeda G protein-coupled receptor 5 (TGR5). These receptors are essential in lipid and glucose metabolism, and impaired bile acid signaling may cause NAFLD. Bile acids also reciprocally regulate the gut microbiota directly via antibacterial activity and indirectly via FXR. Therefore, bile acid signaling is closely linked to dysbiosis and NAFLD. During the past decade, stimulation of bile acid receptors with their agonists has been extensively explored for the treatment of NAFLD in both animal models and clinical trials. Early evidence has suggested the potential of bile acid receptor agonists in NAFLD management, but their long-term safety and effectiveness need further clarification.


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